thermal Physics Flashcards
What is thermal equilibrium
No net transfer of energy between the 3 phases of matter
What is the absolute temperature scale
Uses the triple point of pure water and absolute zero (lowest possible temperature)
Degrees to kelvin : + 273
Describe solids
Regularly arranged
Packed closely together
Strong electrostatic forces
Fixed positions (can vibrate)
Therefore have kinetic energy
What is the internal energy of a substance
The sum of the randomly distributed kinetic and potential energies of atoms or molecules within the substance
Why can you never reach 0K
Because the potential energy of a substance can never be zero, substances always have electrostatic potential energy within the particles
What is the specific heat capacity of a substance
The energy required per unit mass to increase the temperature by 1k
Specific latent heat definition
The energy required to chance the phase (state) per unit mass whilst at a constant temperature
what is the brownian motion
The molecules of a gas travel in random directions with random velocity.
What happens when an object is heated, to its KE and potential energy
When an object is heated but doesn’t change state is KE increases but its potential energy does not.
When an object is heated and it changes state its potential energy increases but its kinetic energy does not
This is why when an object changes state its internal energy increases but its kinetic energy does not
How can SHC be measured
Using an electrical heater WITH INSULATOR to heat a known mass of a substance with known power for a given time.
- Measure initial and final temperatures of a substance
use VIT = energy to calculate SHC
the energy required per unit mass to change the phase of a substance from solid to liquid.
specific latent heat of fusion
